Be warned about Java 7 u1 and Hotspot. Regards, Dave
Begin forwarded message: > From: Konstantin Kolinko <[email protected]> > Date: July 29, 2011 7:35:42 AM PDT > To: Tomcat Users List <[email protected]> > Subject: Fwd: [WARNING] Index corruption and crashes in Apache Lucene Core / > Apache Solr with Java 7 > Reply-To: "Tomcat Users List" <[email protected]> > > Forwarding from announce at apache org. I think it is better to be warned. > > Best regards, > Konstantin Kolinko > > ---------- Forwarded message ---------- > From: Uwe Schindler > Date: 2011/7/29 > Subject: [WARNING] Index corruption and crashes in Apache Lucene Core > / Apache Solr with Java 7 > > Hello Apache Lucene & Apache Solr users, > Hello users of other Java-based Apache projects, > > Oracle released Java 7 today. Unfortunately it contains hotspot compiler > optimizations, which miscompile some loops. This can affect code of several > Apache projects. Sometimes JVMs only crash, but in several cases, results > calculated can be incorrect, leading to bugs in applications (see Hotspot > bugs 7070134 [1], 7044738 [2], 7068051 [3]). > > Apache Lucene Core and Apache Solr are two Apache projects, which are > affected by these bugs, namely all versions released until today. Solr users > with the default configuration will have Java crashing with SIGSEGV as soon > as they start to index documents, as one affected part is the well-known > Porter stemmer (see LUCENE-3335 [4]). Other loops in Lucene may be > miscompiled, too, leading to index corruption (especially on Lucene trunk > with pulsing codec; other loops may be affected, too - LUCENE-3346 [5]). > > These problems were detected only 5 days before the official Java 7 release, > so Oracle had no time to fix those bugs, affecting also many more > applications. In response to our questions, they proposed to include the > fixes into service release u2 (eventually into service release u1, see [6]). > This means you cannot use Apache Lucene/Solr with Java 7 releases before > Update 2! If you do, please don't open bug reports, it is not the > committers' fault! At least disable loop optimizations using the > -XX:-UseLoopPredicate JVM option to not risk index corruptions. > > Please note: Also Java 6 users are affected, if they use one of those JVM > options, which are not enabled by default: -XX:+OptimizeStringConcat or > -XX:+AggressiveOpts > > It is strongly recommended not to use any hotspot optimization switches in > any Java version without extensive testing! > > In case you upgrade to Java 7, remember that you may have to reindex, as the > unicode version shipped with Java 7 changed and tokenization behaves > differently (e.g. lowercasing). For more information, read > JRE_VERSION_MIGRATION.txt in your distribution package! > > On behalf of the Lucene project, > Uwe > > [1] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134 > [2] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7044738 > [3] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7068051 > [4] https://issues.apache.org/jira/browse/LUCENE-3335 > [5] https://issues.apache.org/jira/browse/LUCENE-3346 > [6] http://s.apache.org/StQ > > ----- > Uwe Schindler > [email protected] > Apache Lucene PMC Member / Committer > Bremen, Germany > http://lucene.apache.org/ > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
